I saw Samson Schmidt play last night and he appeared to be using a Rodrigo Shopis without an adjustable truss rod. A buddy of mine told me that the original Selmers had an almuninum insert instead of a truss rod. Is that so? If so, how important is it to actually have a truss rod on a well-made guitar? Is it just something that a lot of us think we have to have but isn't actually critical?
Also, what is the advantage to building without a truss rod? Cost?